[R] Problems when computing the 1rst derivative of mixtures of densities

2006-07-04 Thread Clément Viel
Hi everybody, I am currently working on mixtures of two densities ( f(xi,teta)= (1-teta)*f1(xi) + teta*f2(xi) ), particularly on the behavior of the variance for teta=0 (so sample only comes from the first distribution). To determine the maximum likelihood estimator I use the Newton-Rapdon Iterati

Re: [R] Problems when computing the 1rst derivative of mixtures of densities

2006-07-07 Thread Spencer Graves
What problem are you trying to solve? The mixture proportion you are trying to estimate violates the assumptions that provide a normal approximation to the distribution of maximum likelihood estimators. These situations even violate the assumptions for 2*log(likelihood ratio) being a